1. Field of the Invention
The present inventive concept relates to a semiconductor memory device having a vertical channel and a method of manufacturing the same, and more particularly, to a NAND flash memory device having a vertical channel and a method of manufacturing the same.
2. Description of the Related Art
A conventional 2 dimensional (2D) semiconductor memory device includes memory cells arranged in a 2 dimensional (2D) manner and a horizontal channel. Threshold voltages of the 2D memory cells may be controlled by doping the horizontal channel by ion implantation. A three dimensional (3D) semiconductor memory device proposed to increase the integration density of a semiconductor device includes memory cells vertically stacked and a vertical channel. The vertical channel may be structurally difficult to be doped by ion implantation, as compared to the horizontal channel.